Illegal immigration from the U.S.-Mexico border dropped significantly during his first full month in office, President Donald Trump said in his first Cabinet meeting.

"In the first full month of my administration following the issuance of my executive orders, illegal immigration on our southern border fell by an unprecedented 40 percent," Trump said March 13.

The Department of Homeland Security recently said there had been a 40 percent drop from January to February 2017 in illegal crossings at the southwest border.

How much is Trump to credit for this decline and is it unprecedented? Experts say Trump’s hard-line immigration rhetoric likely played an important role, but other factors are also worth considering. The decline is a significant drop compared with recent years.

Southwest border illegal crossings

On March 8, DHS Secretary John Kelly described an "unprecedented" decline in illegal southwest border crossings from January to February.

Total apprehensions at the southwest border dropped about 44 percent from January (42,504) to February (23,589).

Total apprehensions include:

- U.S. border patrol apprehensions between ports of entry, and

- Inadmissibility determined by U.S. Customs and Border Protection’s Office of Field Operations at ports of entry.

Specifically, the subset of apprehensions by border patrol along the U.S.-Mexico border decreased about 40 percent, from 31,578 in January to 18,762 in February.

CBP historically sees a 10 to 20 percent increase in apprehensions from January to February, Kelly’s statement said. Monthly southwest border apprehension data for fiscal years 2012 to 2016 is available here and shows an uptick in apprehensions from January to February.

But apprehensions may increase in coming months, according to DHS.

"We will remain vigilant to respond to any changes in these trends, as numbers of illegal crossings typically increase between March and May," Kelly said. "However, the early results show that enforcement matters, deterrence matters, and that comprehensive immigration enforcement can make an impact."

Trump immigration orders, implementation memos

Trump touted declines in illegal immigration along the southern border in the first full month of his administration and referenced directives he signed late January.

Among things covered in Trump’s immigration orders and Kelly’s implementation memos: a directive to build a U.S.-Mexico border wall; authorization to hire 15,000 additional employees for immigration enforcement at the border and interior of the country; a stop to the practice of "catch and release," or releasing immigrants caught illegally crossing the border. (Here’s a full recap.)

Experts say Trump’s tough-on-immigration rhetoric played an important part in the reduction of illegal border crossings. But they also caution that one month’s worth of data is not enough to make a complete assessment and that other factors should also be considered.

"I do think that the election of President Trump is probably the most important factor driving these changes. But it is still very early to have firm conclusions," said Christopher Wilson, deputy director of the Mexico Institute at the Wilson Center.

It’s likely that his rhetoric so far has had a stronger effect than his policies, as on-the-ground changes and implementation takes longer, Wilson said.

"The Trump administration’s rhetoric and executive orders have created uncertainty for potential migrants and in immigrant communities, and new fears that immigration enforcement will intensify both at the border and in the U.S. interior," said Faye Hipsman, a policy analyst with the U.S. Immigration Policy Program at Migration Policy Institute, a nonpartisan think tank researching migration trends and policies.

February 2017’s apprehension numbers represent a five-year low, Hipsman said. And the country hasn't seen a 40 percent decline in apprehensions in the last five years. But monthly apprehensions in fiscal year 2011 "were regularly on par with this February’s figures," she said.

"The factors driving today’s border crossers — who are now majority Central American — are unchanged," Hipsman noted. "Violence and insecurity still grip the region, poverty has not improved, and there are still tens of thousands of families living apart with some members in the U.S. and in others in Central America with desires to reunify."

And while apprehension data is generally used to measure illegal border crossings, past administrations have used both high and low apprehension numbers as an indicator of strong border enforcement, said Donald Kerwin, executive director of the Center for Migration Studies, a think tank studying international migration and member of a global network of migrant shelters and service centers.

"That metric can cut both ways," Kerwin said.

Our ruling

Trump said, "In the first full month of my administration, following the issuance of my executive orders, illegal immigration on our southern border fell by an unprecedented 40 percent."

The numbers check out. February apprehensions declined 40 percent.

Calling the decline unprecedented is a bit of a stretch, however. And experts warn that one month’s data is not enough to indicate a trend toward lower illegal immigration and that other factors, aside from Trump’s rhetoric and executive orders, should be considered in analyzing apprehension declines.

Trump’s statement is accurate but needs additional information. We rate it Mostly True.

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